Backup systems may create a copy of data so that the copy may be used to restore the original after a data loss event. Backup systems can be used in disaster recovery, where a complete restoration of the original data may be performed after a storage system crash. Another use for backup system may be to restore small numbers of files in the event an accidental erasure or corruption of the files.
Backup systems can be used in a network environment to back up two or more client devices onto a single backup storage system. Typical installations may perform a backup operation on a periodic basis, such as a daily or weekly backup operation. Some systems may perform a full backup, where all of the original data are backed up, or an incremental backup, where only the changed data from the last backup operation are transmitted.